Motor float is intended for one's ride over water surface, generally in a vertical position of the rider. Thanks to the movement speed, easy manipulation and resistance it allows riding over calm surface as well as in big waves, which are impassable for large and heavy motor floats. On a calm surface rotations with radius up to 4 m in the approach speeds of about 40 km/h are allowed. The float can react quickly when riding on a wave and therefore reach the right place, or easily and safely leave the wave.
Motor float is driven by a combustion engine arranged inside the float. The engine needs sufficient fresh air supply to function properly. Air is sucked into the engine through a carburator, in which it is mixed with fuel in the pre-set ratio. In case of insufficient air supply the engine the performance rapidly decreases and may lead to a complete stopping of engine. During normal driving water pours over the float surface, especially in turns, and the float may sink under the surface even for several seconds. Moreover, when the motor float moves along the water surface with great speed and due to maneouvres, it is exposed to the streaking water, surrounding waves, and in some cases it may turn over under the water surface. Water leaking into the engine section and being sucked by the engine may result into the engine being damaged. Further requirement for proper function of the engine is sufficient air supply inside the engine compartment for the cases when the float is sinked under the water surface for a brief moment.
The present solutions are based on the use of a suction pump or a reverse valve. The U.S. Pat. No. 7,001,232 describes a solution which uses the reverse valve at the suction inlet into the float section and curvature of the suction pipe. The solution is designed for a robust float of great load displacement and low maneuverability. However, it is not suitable for using with light float enabling large angles in turns, jumps, and ride in waves with great speed, because during a more dynamic ride it will not prevent larger leakage of water into the engine compartment. The solutions of water suction from the engine compartment are described in the U.S. Pat. No. 5,582,529 as well as in the U.S. Pat. Nos. 6,192,817 and 6,568,340. These solutions aim to prevent water leakage into the inner space of the float while being tilted. Solution from the U.S. Pat. No. 5,582,529 describes water suction using a pump arranged in the float chamber in front of the engine. However, this pump only functions when the float is in horizontal or slightly tilted position. In case of a greater angle or greater amount of water the space for water suction is overflowed and water reaches the engine. In the solution of the U.S. Pat. No. 6,568,340 is the suction arranged directly on the float, where it is constantly overflowed, which rapidly decreases the volume in the present water separator and thus also the ability to supply sufficient amount of air necessary for the engine performance. Even in this case the problem of tilted float is not solved. Another drawback of this solution is the use of a long pipe for underpressure suction, thanks to which the applicable underpressure as well as the volume of sucked water decreases. The solution of the U.S. Pat. No. 6,192,817 uses the same water separator with added pipe for air supply directly into the engine. Of course, this pipe causes pulses and undesirable resonant pressure waves, which rapidly decrease the performance and stable operation of the engine. There is also a problem of pressure losses resulting from friction between sucked air and pipe walls.